Three N-H functionalized metal-organic frameworks with selective CO2 uptake, dye capture, and catalysis.

Three N-H functionalized metal-organic frameworks, Pb-DDQ, Zn-DDQ, and Cu-DDQ, were synthesized with a new flexible dicarboxylate ligand based on quinoxaline (H2DDQ = N,N'-dibenzoic acid-2,3-diaminoquinoxaline). CO2 adsorptions indicate that Zn-DDQ and Cu-DDQ have greatly enhanced the CO2 uptake due to the opposite N-H groups on pyrazine. With very small adsorption of N2, Cu-DDQ shows high selectivity for CO2 and N2. The three MOFs also have large adsorptions of some selected dyes, while Zn-DDQ and Cu-DDQ with large but different shapes of pores are demonstrated to be promising materials for fast separation of MB/other and CV/other mixtures, respectively. The cyanosilylation of aldehydes and ketones with high yields in a short reaction time for Cu-DDQ indicates that Cu-DDQ has a higher Lewis acidity than the other two MOFs.

Bis[2-(3-pyridinio)benzimidazolium] di-mu-chloro-bis[trichlorocadmium(II)].

The title compound, (C12H11N3)2[Cd2Cl8], consists of two discrete 2-(3-pyridinio)benzimidazolium cations and one [Cd2Cl8]4- anion. The dimeric [Cd2Cl8]4- anion lies about an inversion centre and consists of two distorted [CdCl5] trigonal bipyramids which share a common edge. The two Cd atoms are each coordinated by two mu-Cl atoms and three terminal Cl atoms, with a Cd...Cd separation of 3.9853 (6) A. The packing displays two-dimensional hydrogen-bonded sheets, which are further linked by C-H...Cl contacts and pi-pi stacking interactions to yield a three-dimensional network.